Interpretive Summary: Pests are estimated to cost US farmers and consumers over $130 billion dollars per year. These pests come from many different taxa of biota (insects, pathogens, nematodes, mammals, microbes, plants, etc.) and from all part of the world. Scientists have long realized that many of these pests, are "nonindigenous" to the areas where they cause the most severe damage. These introduced pests have been referred to as "Invasive Species". In Feb of 1999, the damage caused by invasive species reached the severity that an Executive Order was pronounced to create an Invasive Species Council to help address this "widespread national emergency". ARS conducts research on several categories of invasive pests. This article summarizes ARS research on invasive species into several categories. 1) basic pest biology of the invasive species; 2) population dynamics, interactions with the host through predation, parasitism, competition, population increase, spread, etc.; 3) interactions with the larger environment including both biotic and abiotic factors; 4) management tactics, including exclusion, eradication, host plant resistance, biological and integrated control; and 5) sustainable habitat management. Research results in these areas have been summarized and over 100 references provided to recent ARS research

Technical Abstract:
Invasive pests cause huge losses to both agricultural production systems and to the natural environment through displacing native species and decreasing biodiversity. It is now estimated that many thousand exotic insects, weeds and pathogens have been established in the United States and that these invasive species are responsible for a large portion of the estimated $130 billion losses estimated to be lost to pests each year. The Agricultural Research Service has responded with extensive research and action programs aimed at understanding these problems and developing new management approaches for their control. This paper provides an overview of some of the ARS research that has been conducted on invasive species over the past few years and addresses both different categories of research and some specific pest systems of high interest to the US Department of Agriculture.